Stabilizing equipment support devices have been employed for many years in the motion picture and video industry, and in industrial environments to support cameras, tools and other equipment while in use. Examples of such devices include support arms that rely on a pair of spring-powered parallelogram arm sections to isolate and support the equipment. The supports often include a gimbal device to isolate the equipment from the arm motion. Increasingly sophisticated spring-loaded parallelogram arm segments that are interconnected by hinges acting around vertical axes have been designed. Similar hinges may also interconnect the support arms to the operator's semi-rigid harness. These support arms may permit an operator to position extremely heavy payloads in space with minimal force and move them anywhere within reach of his or her own arms with fingertip precision.
Problems arise, however, when the sum of the hinge tolerances and the various parallelogram link bearing tolerances combine to permit the arm to increasingly ‘sag’ (as its hinge pins—spaced from the mount out to the payload—progressively depart from vertical) such as when a camera is held out further and further away from the operator. Close tolerances and rigid materials have become essential in the construction of these arms, but some ‘sag’ is inevitable, and operators have learned to compensate by slightly leaning back away from the camera during these arm extensions, to bias the camera payload so that it stays in place and does not continue to fall away.
‘Hard-mounted’ applications have occasionally been employed. A ‘hard-mounted’ arm is mounted directly to a fixed support, such as a portion of a camera car or camera dolly, so that the operator does not have to bear the load of the equipment, yet still provide the stabilizing effect of the gimbal mount and arm suspension to tune out the bumps as the vehicle progresses.
In these cases, current designs provide no remedy for ‘sag’ as the arm extends and the operator is required to continually hold back the payload with his or her other hand. This has been a serviceable arrangement for camera work, but will be a more significant problem for other applications of the stabilizing equipment. These arms are also used to reduce workplace fatigue and injuries caused by the repetitive lifting and deploying of heavy tools and equipment for industrial applications. These applications are ‘hard-mounted’ in most cases, and therefore a means is required to assist in the natural ‘centering’ of these arms so that they do not tend to fall away from the ideal location of use, if inadvertently displaced either inwardly or outwardly. Industrial users for example, often do not have a free hand to assist in keeping the payload where it is needed laterally, and so a means is required to perform that function.